Fixed mindset‐signalling peer behaviours predict impostor feelings and evaluative concerns

BACKGROUND: Beliefs that ability is fixed can make challenges feel like evidence of inadequacy rather than opportunities to learn. Peers play a powerful role in communicating these beliefs through their everyday words and behaviours, yet prior research has relied primarily on cross-sectional surveys or hypothetical scenarios. AIMS: This research examined how peers' mindset-signalling behaviours relate to impostor feelings and evaluative concerns as they unfold in daily life and as they are remembered. SAMPLES: Study 1 included 130 undergraduates (670 daily reports) enrolled in at least one STEM course, and Study 2 drew on follow-up interviews with 18 of these students. METHODS: Study 1 used a 10-day daily diary design with Bayesian multilevel modelling to examine within-day associations between peer behaviours, impostor feelings and evaluative concerns. Study 2 used retrospective interviews to explore how students interpreted and made meaning of these experiences. RESULTS: On days when students observed peers expressing fixed-mindset cues, such as fixed-ability statements or self-deprecating remarks, they reported higher levels of impostor feelings and evaluative concerns. Observing peers persist through difficulty predicted lower impostor feelings that day. Retrospective interviews echoed these patterns, although different moments stood out in memory. Students most often recalled peers sharing their struggles or offering help as emotionally meaningful experiences. CONCLUSIONS: Peer mindset signals matter both in daily experience and in later memory. Daily verbal cues were associated with same-day impostor feelings and evaluative concerns, whereas remembered moments of vulnerability and support became incorporated into broader emotional narratives.